Look out below: drug cartels are using improvised cannons to hurl packages of drugs across the border and into U.S. territory, reports the Associated Press.

Police in the border city of Mexicali seized a homemade cannons last week, according to the AP. The device, powered by an old car engine converted into an air compressor, can shoot as much as 13 kilos of marijuana from its plastic pipe more than 500 feet — more than far enough to clear the border.

Thanks to the scattered drug packages found on the California side of the border, authorities have long known that those cannons are at work. In Dec 2012, Reuters reported, a U.S. Border Patrol official said 85 pounds of marijuana worth as much as $42,500 was discovered near San Luis, Arizona.

After a thorough search of the area about 200 miles southwest of Phoenix, U.S. Border Patrol agents found a carbon dioxide tank used to propel objects from the cannon, according to Reuters.

The cannons are the smugglers’ latest creative twist in response to tightened cross-border security. In Jan 2011, National Guard troops discovered a medieval-style catapult, apparently used to launch packets of drugs, next to the border fence near the town of Naco, Ariz., according to NBC News.

A National Guard surveillance video shows how several people were testing the device before Mexican authorities disrupted their operation.

According to a 2010 report by Rand Corporation, a global policy think tank, as much as 67 percent of marijuana in the United States comes from Mexico. The Council on Foreign Relations, a U.S. foreign policy think tank, said America spends as much as $3 billion a year on border patrol.